So, not only is the UK 230v, it's also wired in a ring (i.e., your circuit isn't a branch from your junction box, it's a full loop). So, for a given power capacity, you can use much less copper.
UK fixed wiring circuits, unlike those found in almost all other countries, make widespread use of ring circuit designs, as well as radial circuit designs often seen in other countries. (This was one of the recommendations of the Electrical Installations Committee, convened in 1942 as part of the Post War Building Studies programme, which in 1944 determined that the ring final circuit offered a more efficient and lower cost method to support a greater number of sockets.[6]) It continues to be the usual wiring method for domestic and light commercial socket and device wiring in the UK. Lighting circuits, which typically have lower power requirements, are usually radially wired, confusingly sometimes called "loop" wiring.
So, the why is: More power, less copper, and that's really useful when you're resource constrained because someone has declared war on you and is blockading your coast, or you're recovering from that.
(from the wiki: https://en.wikipedia.org/wiki/Electrical_wiring_in_the_Unite...)
So, the why is: More power, less copper, and that's really useful when you're resource constrained because someone has declared war on you and is blockading your coast, or you're recovering from that.